1. Technical Field
The disclosure generally relates to a three dimensional structure, and more particularly, to a three dimensional printing method for forming the three dimensional structure.
2. Description of Related Art
As the technology advanced in recent years, many methods that utilize additive manufacturing technology (e.g. layer-by-layer model construction) to build three-dimensional (3D) physical models have been proposed. Typically, the additive manufacturing technology is to convert data of a 3D model, which is constructed by software, such as computer aided design (CAD), into multiple thin (quasi-two-dimensional) cross-sectional layers that are stacked in sequence. In the meantime, many techniques for forming thin cross-sectional layers are also proposed. For example, a printing module of a printing apparatus is usually configured to move above a base along an XY plane according to spatial coordinates XYZ constructed according to the design data of the 3D model, so as to use a construction material to form shapes of the cross-sectional shapes correctly. Then, the deposited construction material may be cured naturally or by heating or light irradiation to form the desired cross-sectional layers. By moving the printing module along the Z axis layer-by-layer, multiple cross-sectional layers can be gradually stacked along the Z axis, and while the construction material is cured layer-by-layer, a 3D object is formed.
Take the technology that forms 3D objects by curing the construction material with a light source as an example, the printing module is configured to be immersed in a liquid modelling material in a container, and a light source module is disposed on the XY plane to irradiate the liquid modelling material, so as to cure and stack the liquid modelling material on a movable platform of the printing module. Accordingly, by moving the movable platform of the printing module layer-by-layer along the Z axis, the liquid modelling material can thus be gradually cured and stacked into a three dimensional structure. Nevertheless, in terms of the completely formed three dimensional structure, in order to reduce the consumption of the modelling material, the three dimensional structure is often designed with structure features, such as a plurality of hollow portions, so as to lower the production costs. However, as a result, after the hollow portions are sealed by the casing, the liquid modelling material is apt to remained in the hollow portions during the forming process, wherein the remained liquid modelling material can easily affect the structure and the stability of the three dimensional structure. Accordingly, how to reduce the material consumption while preventing the liquid modelling material from being remained in the three dimensional structure during the forming process of 3D printing thus become a problem that should be considered and solved by related practitioners.